<!DOCTYPE html>
<html>
  <head lang="en">
    <meta charset="UTF-8" />
    <title></title>
    <style>
      .login-header {
        width: 100%;
        text-align: center;
        height: 30px;
        font-size: 24px;
        line-height: 30px;
      }

      ul,
      li,
      ol,
      dl,
      dt,
      dd,
      div,
      p,
      span,
      h1,
      h2,
      h3,
      h4,
      h5,
      h6,
      a {
        padding: 0px;
        margin: 0px;
      }

      .login {
        display: none;
        width: 512px;
        height: 280px;
        position: fixed;
        border: #ebebeb solid 1px;
        left: 50%;
        top: 50%;
        background: #ffffff;
        box-shadow: 0px 0px 20px #ddd;
        z-index: 9999;
        transform: translate(-50%, -50%);
      }

      .login-title {
        width: 100%;
        margin: 10px 0px 0px 0px;
        text-align: center;
        line-height: 40px;
        height: 40px;
        font-size: 18px;
        position: relative;
        cursor: move;
      }

      .login-input-content {
        margin-top: 20px;
      }

      .login-button {
        width: 50%;
        margin: 30px auto 0px auto;
        line-height: 40px;
        font-size: 14px;
        border: #ebebeb 1px solid;
        text-align: center;
      }

      .login-bg {
        display: none;
        width: 100%;
        height: 100%;
        position: fixed;
        top: 0px;
        left: 0px;
        background: rgba(0, 0, 0, 0.3);
      }

      a {
        text-decoration: none;
        color: #000000;
      }

      .login-button a {
        display: block;
      }

      .login-input input.list-input {
        float: left;
        line-height: 35px;
        height: 35px;
        width: 350px;
        border: #ebebeb 1px solid;
        text-indent: 5px;
      }

      .login-input {
        overflow: hidden;
        margin: 0px 0px 20px 0px;
      }

      .login-input label {
        float: left;
        width: 90px;
        padding-right: 10px;
        text-align: right;
        line-height: 35px;
        height: 35px;
        font-size: 14px;
      }

      .login-title span {
        position: absolute;
        font-size: 12px;
        right: -20px;
        top: -30px;
        background: #ffffff;
        border: #ebebeb solid 1px;
        width: 40px;
        height: 40px;
        border-radius: 20px;
      }
    </style>
  </head>

  <body>
    <div class="login-header">
      <a id="link" href="javascript:;">点击，弹出登录框</a>
    </div>
    <div id="login" class="login">
      <div id="title" class="login-title">
        登录会员
        <span
          ><a id="closeBtn" href="javascript:void(0);" class="close-login"
            >关闭</a
          ></span
        >
      </div>
      <div class="login-input-content">
        <div class="login-input">
          <label>用户名：</label>
          <input
            type="text"
            placeholder="请输入用户名"
            name="info[username]"
            id="username"
            class="list-input"
          />
        </div>
        <div class="login-input">
          <label>登录密码：</label>
          <input
            type="password"
            placeholder="请输入登录密码"
            name="info[password]"
            id="password"
            class="list-input"
          />
        </div>
      </div>
      <div id="loginBtn" class="login-button">
        <a href="javascript:void(0);" id="login-button-submit">登录会员</a>
      </div>
    </div>
    <!-- 遮盖层 -->
    <div id="bg" class="login-bg"></div>
    <script>
      // 需求/思路:
      // 1 显示隐藏
      // 2 按下鼠标左键不松开，移动鼠标，拖拽login盒子（让鼠标最新的坐标决定盒子的left及top）,松开鼠标时停止拖拽(移出mousemove事件)
      //   获取元素
      var link = document.querySelector('#link');
      var close = document.querySelector('#closeBtn');
      var login = document.querySelector('#login');
      var bg = document.querySelector('#bg');
      var title = document.querySelector('#title');

      //   显示隐藏
      link.addEventListener('click', function () {
        login.style.display = 'block';
        bg.style.display = 'block';
      });
      closeBtn.addEventListener('click', function () {
        login.style.display = 'none';
        bg.style.display = 'none';
      });
      //   拖拽
      // 在title上按下鼠标左键时，记录鼠标相对于login的偏移量
      title.addEventListener('mousedown', function (e) {
        var x = e.pageX - login.offsetLeft;
        var y = e.pageY - login.offsetTop;
        // 因为只有在按下鼠标左键之后才能拖拽，故mousemove事件注册必须写在mousedown的事件处理函数中，而不能直接写在外面
        document.addEventListener('mousemove', move);
        function move(e) {
          // 用鼠标最新坐标控制login的left及top
          login.style.left = e.pageX - x + 'px';
          login.style.top = e.pageY - y + 'px';
        }
        // 鼠标弹起时，清除mousemove
        title.addEventListener('mouseup', function () {
          document.removeEventListener('mousemove', move);
        });
      });

      // // 1. 获取元素
      // var login = document.querySelector('.login');
      // var mask = document.querySelector('.login-bg');
      // var link = document.querySelector('#link');
      // var closeBtn = document.querySelector('#closeBtn');
      // var title = document.querySelector('#title');
      // // 2. 点击弹出层这个链接 link  让mask 和login 显示出来
      // link.addEventListener('click', function() {
      //         mask.style.display = 'block';
      //         login.style.display = 'block';
      //     })
      //     // 3. 点击 closeBtn 就隐藏 mask 和 login
      // closeBtn.addEventListener('click', function() {
      //         mask.style.display = 'none';
      //         login.style.display = 'none';
      //     })
      //     // 4. 开始拖拽
      //     // (1) 当我们鼠标按下， 就获得鼠标在盒子内的坐标
      // title.addEventListener('mousedown', function(e) {
      //     var x = e.pageX - login.offsetLeft;
      //     var y = e.pageY - login.offsetTop;
      //     // (2) 鼠标移动的时候，把鼠标在页面中的坐标，减去 鼠标在盒子内的坐标就是模态框的left和top值
      //     document.addEventListener('mousemove', move)

      //     function move(e) {
      //         login.style.left = e.pageX - x + 'px';
      //         login.style.top = e.pageY - y + 'px';
      //     }
      //     // (3) 鼠标弹起，就让鼠标移动事件移除
      //     document.addEventListener('mouseup', function() {
      //         document.removeEventListener('mousemove', move);
      //     })
      // })
    </script>
  </body>
</html>
